The satisfactory removal of dingy stains from soiled/stained substrates is a particular challenge to the formulator of a detergent composition, which has been enabled by the use of bleach components of hydrophobic type such as preformed hydrophobic peroxyacids or hydrogen peroxide and hydrophobic peroxyacid precursors.
However, consumer acceptance of cleaning and laundry products is determined not only by the performance achieved with these products but the aesthetics associated therewith. The perfume systems are therefore an important aspect of the successful formulation of such commercial products.
They are used to cover up the chemical odours of the cleaning ingredients and provide an aesthetic benefit to the wash process and, preferably the cleaned fabrics.
It has now been found that a problem encountered with detergent compositions comprising the combination of a hydrophobic bleach system and a perfume composition is that of the resulting laundered fabric having a "bleachy" characteristic odour.
Not to be bound by theory, it is believed that the hydrophobic bleach system which is a substantive bleach interacts with the perfume deposited on the fabric surface by degrading said perfume.
The potential for such a problem is enhanced when the detergent composition comprises a high level of surfactants, said problem being due to the ability of surfactants, especially anionic surfactants, to transport the hydrophobic bleaching agent to the fabric surface.
The Applicant has found that the degradation of the perfume at the fabric surface can be a particular problem when the fabric to be cleaned has already build up of encrustated metal ions present. This problem can also further be exarcerbated upon use of a detergent composition having a low builder content and/or of a hard water medium.
The detergent formulator is thus faced with the dual challenge of formulating a product which maximises the soil/stain removal performance without compromising on the aesthetic aspect.
Co-pending application GB 9425876.1 describes perfume raw materials in presence of a hydrophobic bleaching system wherein the source of active oxygen is coated to prevent the oxidation of said perfume raw materials upon storage.
Co-pending application GB 9505518.2 describes detergent compositions comprising perfume raw materials having a strong resistance to oxidation from hydrophobic bleaches.
WO 95/02681 describes sensitive materials such as chelating agents (EDDS), perfume components or hydrophobic bleaches protected from oxidative environment by a specific package.
It is further known to the man skilled in the art that perfumes are composed of volatile ingredients which are susceptible of oxidation upon storage. Accordingly, the perfume composition may be protected from the oxidative environment by encapsulation of the perfume with silica material as described in EP 332259 or adsorption onto porous carrier as disclosed in UK 2,066,839, U.S. Pat. Nos. 4,539,135; 4,713,193, 4,304,675, WO 94/19449 and WO 94/28107. Although efficient to protect the perfume from oxidation upon storage and/or to direct the perfume to the fabric, these materials will still release or leach the perfume out of the material upon wash, exposing thus the perfume to the bleach component at the fabric surface.
Notwithstanding the advance in the art there is still a need for a detergent composition which provide effective soil/stain removal performance together with an effective residual perfume scent on laundered fabrics.
The Applicant has now found that this problem can be overcome by the provision of a metal ion sequestrant present at high levels within the detergent composition.
The further addition of an organodiphosphonic component has been found to be beneficial to the overall performance of the detergent composition.